Mechanical tobacco smoke filter



United States Patent [72] inventor Jon W. Beam Cushing, Oklahoma [21] Appl.No. 861,127 [22] Filed Sept. 25, 1969 [45] Patented Oct. 13, 1970 [73] Assignee R. J. Reynolds Tobacco Company Winston-Salem, North Carolina a corporation of New Jersey Continuation of application Ser. No. 755,060, Aug. 26, 1968, now abandoned.

[54] MECHANICAL TOBACCO SMOKE FILTER 5 Claims, 3 Drawing Figs.

52 0.5.01 131/103, l3l/l0.5,l3l/l0.7,131/215 51 1m.c1 A24 1, 01 /04, A24f07/04 so FieldofSearch 131/103.

3,373,750 3/1968 Beam l31/lO.7X

FORElGN PATENTS l,495,l69 8/1967 France Ul3l/Zl5(B)MX Primary Examiner-Aldrich F. Medbery Assistant Examiner lames H. Czerwonky AI1orney-Pendleton, Neuman Williams & Anderson ABSTRACT: A tobacco smoke filter is provided for attachment to one end of a tobacco rod. The filter includes a pair of capsulelike cylindrical sections, each section having an upstream-facing open end and a downstream-facing closed end, the latter end having formed therein an axially-aligned hole. The sections are arranged in a partially telescoping relation with the closed ends thereof in longitudinally spaced relation and defining the end limits of an elongated cavity. Disposed within the cavity is a valve member biased to assume a hole-closing position with respect to the closed end of the upstream telescoping section. The valve member automatically moves to a hole-uncovering position upon a predetermined suction being applied to the downstream end of the filter. When the valve member is in its hole-uncovering position, the smoke is permitted to flow at a high velocity outwardly past the valve member and impinges against a cavityforming surface and efiects deposition thereon of liquid and solid smoke particles.

MECHANICAL TOBACCO SMOKE FILTER This is a continuation of application Ser. No. 755,060, filed Aug. 26, 1968, now abandoned.

BACKGROUND OF THE INVENTION Considerable effort has heretofore been expended in various attempts to develop a practical filter which wouldremove the liquid and solid smoke particles by utilizing the aerodynamics of the smoke stream so as to produce a smoke impingement effect. Although some encouraging results have been achieved with prior filters utilizing this phenomenon, such filters, however, have been plagued with production costs and operational problems and thus have not been generally accepted by the tobacco industry and the smoking public. The problems involving production costs arise to a large extent from the utilization of extremely small holes and/or tubes which were required to be precisely sized and located so as to effect the increased acceleration of the smoke velocity at certain locations within the filter. The operational problems, on the other hand, were caused by the extremely small holes and tubes becoming readily clogged or plugged shortly after the smoking had begun and thus producing a hard draw or high pressure drop across the filter.

SUMMARY OF THE lNVENTlON Thus, it is an object of this invention to provide an impingement type smoke filter which does not require the utilization of a plurality of extremely small holes and/or tubes to impart a high velocity to the smoke flow.

It is a further object of this invention to provide an impinge- I ment type smoke filter which is of simple, inexpensive construction, effective in operation, and may be readily assembled by mechanical means, the function and operation of which are well known in the cigarette-making art.

It is a still further object of this invention to provide an impingement type smoke filter which may be readily adapted for use in cigarettes, cigars, pipe stems, or detachable cigaratte and cigar holders.

It is a still further object of this invention to provide an impingement type filter which maintains a substantially constant pressure drop thereacross notwithstanding the smoking rate.

It is a still further object of this invention to provide an impingement type filter embodying an absorbent mass wherein the efficiency of the latter is materially increased.

Further and additional objects will appear from the description, accompanying drawings, and appended claims.

in accordance with one embodiment of this invention an impingement type smoke filter is provided which includes a pair of capsule-like cylindrical sections having upstream-facing open ends and downstream-facing closed ends. The closed end of each section is provided with a centrally disposed hole. The sections are arranged in a partial telescoping relation with the open end of the upstream section being affixed to one end of a tobacco rod. The closed ends of the telescoping sections define the end limits of an elongated cavity. Disposed within the cavity is a valve member which is biased to overlie and close off the hole formed in the closed end of the upstream section. When a predetermined suction is applied to the downstream end of the filter, the valve member will automatically move to a hole-open position whereby smoke will pass therethrough and then outwardly past said valve member at a high velocity and impinge against a cavity-forming surface causing liquid and/or solid particles entrained in the smoke to be deposited thereon.

DESCRIPTION For a more complete understanding of the invention reference should be made to the drawings wherein:

FIG. 1 is a side elevational view of a filter cigarette embodying a preferred form of improved filter, the latter being shown in longitudinal section.

FIG. 2 is similar to FIG. 1, but showing the component parts of the filter in exploded relation.

FIG. 3 is similar to FIG. 1, but showing a modified fonn of the improved filter adapted to be detachably connected-to one end ofa tobacco rod.

Referring now to the drawings and more particularly to FIG. 1, a filter cigarette 10 is shown which embodies a preferred form of the improved impingement filter ll. The filter is affixed to one end of a tobacco rod 12, the latter comprisingia core 13 of compacted shreds of blended tobacco, which is encompassed by a sleeve 14 of suitable cigarette paper.

Filter 11 in the illustrated embodiment includes a pair of capsule-like cylindrical sections 15 and 16. The sections are of like configuration and each includes an upstream-facing open end or and a downstream-facing rounded closed end 15b or 16b. The closed end in each instance is provided withia centrally disposed opening 15c or .l6c which may vary in diameter size from approximately .03 1 inches to approximately .125 inches. The sections 15 and 16, if desired, may be formed from conventional plastic, double zero size medicinal capsule components. However, said sections also may be formed from other types of material such as foil, wax impregnated paper, etc.

The sections 15 and 16 are arranged in partial telescoping relation; that is to say the closed end 15b of the upstream section-1'5 is inserted approximately .250 inches into the open end 16a of the downstream section 16. By reason of this arrangement, an elongated cavity 17 is formed which "is delimited by the closed ends 15b and 16b and the cylindrical wall 16d of section 16.

Positioned within cavity 17 is'a valve member'l8, which'in the illustrated embodiment is in the form of a conventional plastic, single zero size capsule component. Other types'of valve members may be used, if desired, in place of the onelustrated. Valve member 18 is biased by a resilient piece 20 so that the open-end 18a of member 18 overlies and closes off hole 15c formed in the closed end l5b-of the section .15. The downstream end 18b of member 18 is closed and is engaged by the resilient piece 20.

The'resilient piece -20 may be formed ofa suitable porous material such as sponge latex, or it may'take theform of a spring. 'In any case, the resilient piece 20 should be so'constructed asto permit the smoke to pass from the cavity- 17, through the porous material and out through the hole 16c formed in the closed end 16b of sectionl6. The spring tension exerted by piece 20 on valve member 18 shall be suchthatthe latter will move to its hole-opening position when the pressure differential is approximately Z-k inches of H 0.

Once the valve member has assumed its open position, the smoke will flow through hole 150 andthen outwardly around theportionofthe-member l8 defining'the open end-thereof. Because the movement of the valve member is only a short distance, the annular opening, formed between the open end of-thevalve member l8 and the closedend 15b of section 15 and through which the smoke must pass, is -very .narrow, thereby resulting in the velocity of the smoke passing therethrough'being materially increased. lnview of the high velocity'of the emitted smoke, the latter is caused'to impinge against the interior'surfaceof section portion 16d whereupon the liquid and/or solid particles entrained in the smoke are deposited thereon, prior to the smoke passing outthrough hole l6c.

Because of the movement of the valve member and thefact that'the shape of the orifice or passageway through which the smoke is caused to flow is annular, there is no clogging or plugging up of the passageway by the smokeparticles andthus no significant change occurs in the pressure drop across the filter. Furthermore, the resilient piece 20 assures'thatthe passageway maintains the proper dimension in -order :to

produce desired smoke velocity. Thus, the need for small disposed between the closed end b and the end of the tobaccorod 12. Prior to valve member 18 being moved to'i ts open position, the smoke accumulates within section 15 and'thus,

the smoke more effectively permeates or is entrapped within the absorbent plug 21 enhancing the filtering efficiency thereof.

The capsule-like sections 15 and 16 are frictionally retained in their assembled relation and in turn are affixed to the adjacent end of the tobacco rod by a sleeve 22 of tipping paper or the like.

In the modified form 100 of the filter shown in FIG. 3, no sleeve is required to affix the sections to the end of the tobacco rod. To facilitate assembly of the filter 100 on the end of the tobacco rod or cigarette, the open end 115a of the capsule-like section 115 is flared outwardly a slight amount as i seen in FIG. 3. To retain the two sections 115 and 116 in partial telescoping relation, the latter may be partially overwrapped by a sleeve 123 of suitable material such as paper or film.

Thus, it will be seen that an impingement type filter has been provided which is formed of a few inexpensive parts, is simple to assemble and is effective in removing liquid and solid particles from the smoke. The improved filter does not require a plurality of small carefully shaped and located holes or tubes through which the smoke is required to flow. The improved filter maintains a substantially uniform pressure drop telescoping relation, each section having anupstream-facing open end and a downstream-facing closed end, each closed end being provided with an aperture through which smoke from the lighted tobacco rodis caused to flow upon a predetermined suction being exerted on the downstream end of the filter, the closed ends of said sections being in longitudinally spaced relation and defining the end limits of an elongated vcavity; and a valve member and a resilient, porousmaterial bias means disposed within said cavity, said valve member being biased by said bias means to assume a closed position with respect to the closed end aperture formed in said upstream section, said valve member assuming an apertureopen position upon said predetermined suction being exerted on said filter downstream end, and cooperating with the adjacent closed end of said upstream section to form a narrow tion has a capsule-like configuration and the closed end thereof is substantially hemispherical.

3. The smoke filter of claim 1 wherein said bias means is disposed intermediate said valve member and the closed end of the downstream section and exerts a predetermined bias on said valve member.

4. The smoke filter of claim 1 including a mass of absorbent filter material disposed within the open end of said upstream section and adjacent the closed end of said upstream section,

the smoke passing through said mass prior to passing through the aperture in said upstream section closed erid.

5. The smoke filter of claim 1 wherein the portion of said upstream section delimiting the open end thereof is outwardly 4 flared so as to facilitate insertion of an end of the tobacco rod into the upstream section open end. 

